Process of making sheet metal



llwrrnn STATES PATENT FFlCE.

EVAN J. FRANCIS, OF NEW KENSINGTON, PENNSYLVANIA.

PROCESS OF MAKING SHEET METAL.

, SPECIFICATION forming part of Letters Patent No. 626,994, dated June13, 1899.

m utation filed'Novemlier 18,1898. Serial No. 696,804. (No specimens.)

To all whont it may concern:

Be it known that I, EVAN J. FRANCIS, a resident of New Kensington, inthe county of \Vestmoreland and State of Pennsylvania, have invented anew and useful Improvement in Processes of Making Sheet Metal; and I dohereby declare the following to be a full, clear, and exact descriptionthereof.

My invention relates to a process for the manufacture of sheet met-a1.

One of the greatest difficulties encountered in connection with themanufacture of sheet iron and steel for tinning and otherpurposes is dueto the oxidation of the iron or steel either in the original form ofbars or plates or when reduced to sheets. Toremove anyscale caused bythe oxidation of the metal, it has to be carefully annealed and pickledat different stages of the process. If the sheets when reduced are to betinned or coated with another soft metal or alloy, unless all oxid hasbeen removed previous to the dipping or coating operation an imperfectsheet will result, as the coating metal will not take effect on thespots where oxidation has taken place and Where any scale remains.

The object of my invention is to provide a process of making sheet metalin which the liability of the oxidation of the metal is practicallyeliminated, so that the sheet when finished, whether to be finallycoated with another metal or not, will be free from oxid and the dangerof oxidation, while at the same time the sheet metal possesses greattougl1 ness and ductility for stamping and other uses in the arts.

To these ends my invention consists, generallystated, in coating theiron or steel body from which the metal sheet is to be formed withnickel, such as by electrolysis, heating the metal body thus coated, andthen reducing the same to sheet metal of desired gage, and, if desired,in coating the sheet metal so produced with tin or other soft metal, inwhich case the invention includes certain economical treatment of thesheets in the tinning or like process.

In practicing my invention I take iron or steel in the form of billets,bars, or plates and remove any oxid which it may have on its surface.This is preferably done in the ordinary manner by introducing the metalinto a suit tion is to be carried out in connection with the manufactureof tin-plate, this pickling may be accomplished very economically by theuse of the refuse from the pickliug-pots, into which the sheets areintroduced preparatorytothetinningoperation. The metalbody when cleanedas above is then coated with nickel. This may be accomplished in anysuitable way. I prefer to insert the bars or plates in a suitable bathand deposit the nickel thereon by electrolysis, in this way obtaining acomparatively thin coating of the metal upon the metal bar or plate. Thenickel completely envelops the iron or steel and finds its way into theseams and pores of the metal from which the oxid has been re moved. Thewell-known quality of nickel to resist oxidation and corrosion is thusimparted to the surface of the iron or steel, so that the formation ofrust or scale is avoided. The metal thus coated is then heated to theproper degree and rolled or hammered to reduce said metal to sheets ofthe required thickness or gage. The melting-point of the nickel is sohigh that the coatingis not afiected in raising the metal body to arolling heat. The bars or plates and the thicker sheets formed from themin reducing the metal to the desired gage can also be rolled in pileswithout liability of the nickel coating of any two bars or sheetsadhering, and they can therefore be handled in the same way as inrolling ordinary sheet-iron, while the sheets in the packs formed areeasily separated. By the rolling of the metal the nickel is driven orforced into the pores of the metal, increasing its density,as well asits power to resist oxidation. In the rolling operation the coating ofnickel is of course spread out in a thinner coating; but even when notperceptible to the eye it apparently gives this protection againstoxidation. The nickel when pressed or forced into the pores of the ironor steel adds toughness and ductility, so that sheet metal made in. thismanner can be bent or twisted without fracture or rupture, which givesit great advantage as a stamping-iron. The original coatin g applied byelectrolysis may be itself quite thin, and as the surfaces of the barare small v With tin, the sheets are first pickled to re:

move any possible oxid, and then placed in annealing-boxes andintroduced into a suitable furnace to be annealed in the ordinarymanner. After they have been annealed they are passed through thecold-rolls. They are then taken to the tin-house, Where they may betinned by any of the Well-known methods.

By my process on account of the greater ductility of the sheet metal Iam enabled to dispense with the second annealing, which follows thecold-rolling in the ordinary process of'manufacturing tin-plate. Thepreparation of the metal for tinning, by first rendering itpracticallynon-oxidizable,is ofgreat importance, as the sheets are practically freefrom oxid andscale and better adapted to receive the tin.- There is aclean surface to take the tin, so that no spots remain uncovered, but asmooth even coating of tin is obtained. Again, the tinplate producedfrom metal treated as above will have all the increased toughness andductility which such metal is found to possess, so that a high grade oftin-plate is produced for stamping andother purposes.

Ternc-plate can also be made in the same manner as tin-plate, which Willgive a roofingplate capable of affording greater resistance to theoxidation and corrosion from exposure to the Weather.

I wish to include Within the scope of my invention any process ofcoating ironor steel ductility having marked advantages in such case.

By my invention ordinary Bessemer steel when treated as above takes theplace of the more expensive open-hearth steel.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. The process of making sheet metal consisting in coating an iron orsteel body with nickel, heating the body as coated and reducing it tosheet metal.

2. The process of making sheet metal, consisting in depositing nickel onan iron or steel body by electrolysis, heating the body so coated, andreducing it to sheet metal.

.The process of making sheet metal, con sisting in cleaning an iron orsteel body'from oXid, coating it With nickel, heating the body so coatedand reducing it to sheet metal.

l. The-process of making sheet metal, consisting in coating bars of ironor steel With nickel, piling said coated bars and heating and rollingthem to sheets.

5. The process of making sheet metal, consisting in coating an iron orsteel body with nickel,- heating the'body so coated and reducing it'tosheets, and afterward coating the sheets thus produced with soft metal.

6. The process of making sheet metal, consisting in coating anviron orsteel body with nickel, heating and reducing the body so coated tosheets, annealing said sheets, passing them through cold-rolls, andfinally coating the sheets with soft metal.

7. The process of making sheet metal,consisting in coating an iron orsteel body with nickel, heating and reducing the body so coated tosheets, pickling and annealing said sheets, passing them throughcold-rolls, and finally coating them with soft metal.

In testimony whereof I, the said EVAN J. FRANCIS, have hereunto set myhand.

, EVAN J. FRANCIS. Witnesses:

R0121. D. ToTTEN, ROBERT C. To'rTEN.

